Time-Temperature Shift of Mechanical Properties

2014 ◽  
pp. 189-222
Author(s):  
Helmut Münstedt ◽  
Friedrich Rudolf Schwarzl
Keyword(s):  
Mechanical Properties ◽  
Temperature Shift

Experimental investigation and modeling of dynamic thermomechanical behavior of 4-harness satin weave carbon/epoxy composites

2017 ◽  
Vol 31 (9) ◽  
pp. 1181-1203 ◽  
Author(s):  
Xueyao Hu ◽  
Hui Guo ◽  
Weiguo Guo ◽  
Feng Xu ◽  
Longyang Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Composite Laminates ◽  
Failure Modes ◽  
Shear Failure ◽  
Experimental Studies ◽  
Temperature Shift ◽  
Thermomechanical Coupling ◽  
Longitudinal Splitting ◽  
Wide Range

Theoretical and experimental studies on the compressive mechanical behavior of 4-harness satin weave carbon/epoxy composite laminates under in-plane loading are conducted over the temperature range of 298–473 K and the strain rate range of 0.001–1700/s in this article. The stress–strain curves of 4-harness satin weave composites are obtained at different strain rates and temperatures, and key mechanical properties of the material are determined. The deformation mechanism and failure morphology of the samples are observed and analyzed by scanning electron microscope (SEM) micrographs. The results show that the uniaxial compressive mechanical properties of 4-harness satin weave composites are strongly dependent on the temperature but are weakly sensitive to strain rate. The peak stress and elastic modulus of the material have the trend of decrease with the increasing of temperature, and the decreasing trend can be expressed as the functional relationship of temperature shift factor. In addition, SEM observations show that the quasi-static failure mode of 4-harness satin weave composites is shear failure along the diagonal lines of the specimens, while the dynamic failure modes of the material are multiple delaminations and longitudinal splitting, and with the increasing of temperature, its longitudinal splitting is more serious, but the delamination is relatively reduced. A constitutive model with thermomechanical coupling effects is proposed based on the experimental results and the increment theory of elastic–plastic mechanics. The experimental verification and numerical analysis show that the model is shown to be able to predict the finite deformation behavior of 4-harness satin weave composites over a wide range of temperatures.

Structure and Mechanical Properties of Welded Joints for Nuclear Power Plants of Type MIR 1200

2017 ◽  
Vol 891 ◽  
pp. 201-205
Author(s):  
Ladislav Kander ◽  
Petr Čížek ◽  
Šárka Hermanová ◽  
Zdeněk Říha
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Shear Fracture ◽  
Low Cycle Fatigue ◽  
Water Environment ◽  
Temperature Shift ◽  
Pressure Vessels

The paper deals with research, development and verification of production technology of selected welded joints for pressure vessels of primary circuits of nuclear power plants of type MIR 1200. Effect of various welding technology including simulation heat treatment on mechanical and fracture properties have been studied. Four type of homogenous 10GN2MFA – 10GN2MFA type of welded joints have been prepared for experimental programme. Conventional mechanical properties (tensile and impact test) as well as unconventional mechanical properties (fracture mechanics, low-cycle fatigue and stress corrosion cracking in water environment) have been studied. Effect of elevated working temperature on structure and material properties has been evaluated. Temperature dependencies of shear fracture have been plotted and effect of welding procedure on transition temperature shift has been evaluated. Experimental data have been compared with numerical simulation using FEM.

Effects of PP-G-MA and Epoxy Resin on Morphology and Mechanical Properties of the PP/LGF Composites

2013 ◽  
Vol 652-654 ◽  
pp. 110-115
Author(s):  
Kai Zhou Zhang ◽  
Qiang Guo ◽  
Jian Bing Guo ◽  
Dao Hai Zhang
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Interfacial Adhesion ◽  
Temperature Shift ◽  
Interfacial Interaction ◽  
Scanning Calorimetry ◽  
Glass Fiber Reinforced ◽  
Long Glass Fiber ◽  
Pp Composites ◽  
Morphology And Mechanical Properties

The effects of polypropylene grafted with maleic anhydride (PP-g-MA) and epoxy resin (ER) on the interfacial interaction of the long glass fiber reinforced PP composites were investigated by means of scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and mechanical properties. The experimental results demonstrate that PP-g-MA and ER could effectively improve interfacial interaction between the PP and LGF. Based on SEM, good interfacial adhesion between PP and LGF in PP/ PP-g-MA/ER/LGF composite was observed. DSC results showed that the existense of PP-g-MA or ER caused crystallization temperature shift to low temperature, and melting temperature shift to high temperature. All results in this paper were consistent, and showed the good interaction between PP and LGF, which were proved by the mechanical properties of the composites.

Influence of Temperature and Time Shifts on the Densification of Randomly Oriented Carbon/Carbon Composite

2015 ◽  
Vol 65 (5) ◽  
pp. 411 ◽  
Author(s):  
Thakur Sudesh Kumar Raunija
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
Density Measurement ◽  
Temperature Shift ◽  
Carbon Composite ◽  
Sem Analysis ◽  
Time Shift ◽  
Moderate Increase ◽  
Pressing Method ◽  
Made In

<p>The efforts were made to improve the hot-pressing method of carbon/carbon (C/C) composite fabrication. The C/C composite was fabricated by hot-pressing the slurry moulded compact followed by carbonisation. The temperature and time shifts during hot-pressing were made in order to see their effect on the densification. Their effect was checked through visual inspection, density measurement, scanning electron microscope (SEM) analysis, and mechanical properties evaluation. The results showed that the temperature shift yielded in significant increase in the density after hot-pressing. Further, the density pick up instead of fall after carbonisation was noticed. The results further showed that the time shift too yielded in significant enhancement of density after hot-pressing and showed the pattern after carbonisation similar to the temperature shift. And also showed that the shifts of both temperature and time yielded in significant increase in density and moderate increase in mechanical properties.</p>

Preparation and Properties of the Glass Fiber Reinforced PP Composites

2012 ◽  
Vol 557-559 ◽  
pp. 209-214
Author(s):  
Jian Bing Guo ◽  
Kai Zhou Zhang ◽  
Bin Xue ◽  
Shu Hao Qin
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Interfacial Adhesion ◽  
Temperature Shift ◽  
Interfacial Interaction ◽  
Scanning Calorimetry ◽  
Glass Fiber Reinforced ◽  
Pp Composites ◽  
Scanning Electron

The effects of polypropylene grafted with maleic anhydride (PP-g-MA) and unsturated polyester (UP) on the interfacial interaction of PP/GF composites were investigated by means of scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and mechanical properties. The experimental results demonstrate that PP-g-MA and UP could effectively improve interfacial interaction between the PP and GF. Based on SEM, good interfacial adhesion between PP and GF in PP/UP/GF and PP/ PP-g-MA /GF composites was observed. DSC results showed that the existense of PP-g-MA or UP caused t crystallization temperature and melting temperature shift to high temperature. All results in this paper were consistent, and showed the good interaction between PP and GF, which were proved by the mechanical properties of the composites.

scholarly journals Mechanical characterization of composite solid rocket propellant based on hydroxy-terminated polybutadiene

2016 ◽  
Vol 70 (5) ◽  
pp. 581-594 ◽  
Author(s):  
Nikola Gligorijevic ◽  
Vesna Rodic ◽  
Sasa Zivkovic ◽  
Bojan Pavkovic ◽  
Momcilo Nikolic ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characterization ◽  
Natural Aging ◽  
Temperature Shift ◽  
Relaxation Modulus ◽  
Solid Rocket Propellant ◽  
Rocket Propellant ◽  
Solid Rocket ◽  
Composite Solid

This paper presents the procedure of uniaxial mechanical characterization of composite solid rocket propellant based on hydroxy-terminated polybutadiene (HTPB), whose mechanical properties strongly depend on temperature, strain rate, natural aging and accumulated damage. A method of processing data is presented in order to determine time-temperature shift factor and master curves for tensile strength, ultimate strain and relaxation modulus, depending on reduced time. Functional dependences of these features represent an input for structural analysis of a rocket motor propellant grain. The effects of natural aging on the mechanical properties are also considered.

scholarly journals Lightweight Microlattice With Tunable Mechanical Properties Using 3D Printed Shape Memory Polymer

2018 ◽  
Author(s):  
Chen Yang ◽  
Manish Boorugu ◽  
Andrew Dopp ◽  
Howon Lee
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Three Dimensional ◽  
Temperature Shift ◽  
Spatial Arrangement ◽  
Mechanical Metamaterials ◽  
3D Printed ◽  
Varying Environments

Metamaterials are architected artificial materials engineered to exhibit properties not typically found in natural materials. Increasing attention has recently been given to mechanical metamaterials with unprecedented mechanical properties including high stiffness, strength, or/and resilience even at extremely low density. These unusual mechanical performances emerge from the three-dimensional (3D) spatial arrangement of the micro-structural elements designed to effectively distribute mechanical loads. Recent advances in additive manufacturing in micro-/nano-scale have catalyzed the growing interest in this field. This work presents a new lightweight microlattice with tunable and recoverable mechanical properties using a three-dimensionally architected shape memory polymer (SMP). SMP microlattices were fabricated utilizing our micro additive manufacturing technique called projection micro-stereolithography (PμSL), which uses a digital micro-mirror device (DMD™) as a dynamically reconfigurable photomask. We use a photo-crosslinkable and temperature-responsive SMP which can retain its large deformation until heated for spontaneous shape recovery. In addition, it exhibits remarkable elastic modulus changes during this transition. We demonstrate that mechanical responses of the micro 3D printed SMP microlattice can be reversibly tuned by temperature control. Mechanical testing result showed that stiffness of a SMP microlattice changed by two orders of magnitude by a moderate temperature shift by 60°C. Furthermore, the shape memory effect of the SMP allows for full restitution of the original shape of the microlattice upon heating even after substantial mechanical deformation. Mechanical metamaterials with lightweight, reversibly tunable properties, and shape recoverability can potentially lead to new smart structural systems that can effectively react and adapt to varying environments or unpredicted loads.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

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